America's Cup- Two boat trialling begins on the Hauraki Gulf

A significant milestone in the 34th America's Cup occurred today on the Hauraki Gulf when two AC45's being sailed by crews from Oracle Racing lined up for a two boat practice session. It is believed to be the first time that two AC45's have lined up against each other.

Viewers from the shore, were treated to a glimpse of what match racing could be like in the smaller version of the AC72 catamaran to be used in the 34th America's Cup.

Despite having a helicopter in attendance for much of the session no images, video or story was published by either the official America's Cup website or the Oracle Racing site.

From the shore the view of the yachts was not significantly different to that of watching two monohulls sail on the course area used for the 2000 and 2003 Louis Vuitton and America's Cups.

While Sail-World watched the yachts went through a beat. There was no noticeable difference between what would have been expected from a pair of monohulls two boat trialling and match racing, as opposed to straight line speed testing.

Tacking speeds compared to monohulls looked to be very comparable. There is no such thing as a slow speed tack in these boats, as the acceleration out of the tack is very fast, and the tack duration only five to six seconds. Although we did not see the boats engage in a 10-12 tack duel we did see for or five tacks over a period of six to seven minutes - more than enough to be able to check who had gained and who had lost, and to maintain spectator interest.

The much vaunted speed superiority of the catamaran over the monohull (with the multihull being 40% faster through the water) was no really apparent either, and the two boats looked to be very evenly matched, as would be expected for one-designs.

Oracle Racing "venetian blinding" on an earlier day on the Waitemata Harbour

From a distance there was not a lot of visible difference between the two in terms of rigs.

Of course the soft sailed, monohull America's Cup yachts had their own style, as do the wingsailed catamarans. The illusion of similarity was aided by the AC45's sailing with their jibs - and the rig profile looked similar albeit it smaller than the monohulled America's Cuppers used in 31 of the 33 America's Cup Matches sailed to date.

The big difference was the spectacular hull flying, visible from some angles - which put the unique mark on the closed sailing session sailed in a beautiful late summer sea breeze off Auckland's East Coast Bays.

Up close the views if the two yachts closing in before a tack would have spectacular, however those images will have to wait for another day.

Mast height is an interesting point of comparison between the three boat types with the AC45's carrying a mast of 21.5 metres tall, the ACCV5 used in the 2007 America's Cup measures in at 32.5 metres, the AC72s will be almost five metres taller again at 37 metres high.

To scale off the image at the top of the page, the wingsails on an AC72 will be 1.7 times the AC45 rig height and 1.6 times the hull length of the AC45. They will be shorter but with a five metre taller rig than the America's Cup monohulls.

All told there are now five AC45's in various states of readiness in Auckland - being Artemis Racing, Emirates Team New Zealand, Mascalzone Latino (under charter to Oracle Racing), Oracle Racing and the prototype AC45.